This invention relates to linear ball slides for use with precision instruments and the like, and more particularly to an improved such slide which includes a novel rack and pinion adjusting mechanism.
Ball slides of the type described normally comprise a generally rectangularly shaped base or female section having in its upper surface an elongate, generally rectangular groove which opens on opposite ends of the female member. A male slide member is mounted for reciprocable sliding movement in the groove in the female member by virtue of two sets of ball bearings, which are interposed between the opposed, longitudinal side edges of the male member, and the confronting side edges of the groove formed in the female member. Thus, the slide member is supported at opposite sides thereof by the two sets'of ball bearings for longitudinal sliding movement in the groove formed in the base member. By way of example, typical such linear ball slides are disclosed in U.S. Pat. Nos. 4,334,717, 3,113,807, 5,106,207 and 5,374,128 , all of which patents are assigned to the same Assignee as the instant application.
A common feature of the above-noted prior art ball slides is the substantially friction-free connection provided by the two sets of ball bearings between the male slide member, and the female base member. This same frictionless mounting feature, however, often requires that the ball slide be connected to or be provided with a separate friction clutch or braking device, which will function to secure one member against movement relative to the other after the movable section of the slide has been adjusted into a desired position. For example, when one of the two members of a conventional ball slide is connected to a manually operated lens focusing mechanism which must be smoothly and accurately adjusted to a predetermined position, it is necessary, once such a position has been reached, to brake the movement of one member of the ball slide relative to the other so that the objective lens of the instrument will remain in the desired, focused position. The necessary intensity of this braking effect will of course vary depending upon the nature of the instrument manipulated by the slide, but obviously will be more critical for applications in which the adjustment of one slide member relative to the other is in the vertical direction.
It is an object of this invention, therefore, to provide a novel, modified ball slide having friction drive means for shifting one member of the slide relative to the other, and operative normally frictionally to resist relative movement between the two members of the slide.
A more specific object of this invention is to provide a modified linear ball slide in which one of the two members of the slide is supported at one side thereof by a series of ball or roller bearings, and at its opposite side by a cooperating rack and pinion mechanism which is operable to effect precise and smooth adjustment of one member of the slide relative to the other.
Still another object of this invention is to provide an improved, modified ball slide of the type described having friction means interposed between the two members of the slide, and operative frictionally to resist movement of one member of the slide relative to the other.
Other objects of this invention will be apparent hereinafter from the specification and from the recital of the appended claims, particularly when read in conjunction with the accompanying drawings.